The invention relates to a process for the preparation of a sulphided fluorine-containing nickel-tungsten catalyst.
Such catalysts and a process for their preparation are known from the Netherlands patent application 7514824. As starting material for the preparation of such catalysts certain aluminum hydroxide hydrogels are used.
At least part of the fluorine is incorporated into an aluminum hydroxide hydrogel, whereupon the material is dried and calcined. The metals are incorporated into the calcined material by impregnating the latter with an aqueous solution containing a nickel and a tungsten compound.
The sulphidation, i.e., sulphiding, of the catalysts may be carried out by any method known in the art. Such catalysts have been found to be very suitable, inter alia, for the preparation of high viscosity index lubricating oils by hydrocracking a mixture of heavy hydrocarbons and for application in other processes in which hydrocarbons are converted at elevated temperature and pressure and in the presence of hydrogen. A process has now been found for the preparation of such a catalyst, in which a catalyst can be prepared which is substantially more active than that prepared by the known method. According to said process a catalyst is prepared by starting from a solution which contains a tungsten compound and an aluminum compound from which a tungsten- and aluminum-containing compound is formed.